476 



SCIENCE. 



[Vol. XIII. No. 333. 



The net commercial efficiency of the plant, taking into account 

 all elements of loss, including that in the conducting wires, is about 

 70 per cent : in other words, 70 per cent of the power applied to 

 the shafts of the generators in the underground chamber is deliv- 

 ered for work at the main line shaft in the mill. 



The waste water from the 1,650-foot level of the ChoUar Mine is 

 piped into the Sutro Tunnel. It is now proposed to use this water 

 a third time at a lower level for other work, by means of a similar 

 application of electrical machinery. 



It was expected at the outset that many difficulties would be met 

 in an installation of such novel and original character, which was 

 also by far the largest ever attempted. The projectors, the Brush 

 Electric Company and their agents, the California Electric Light 

 Company, who assumed charge of the details of the erection, were 

 very greatly pleased to find that their forethought had eliminated 

 the troubles anticipated and predicted in almost all respects. Two 

 purely technical difficulties were encountered when the plant was 

 started experimentally, which caused some delay and anxiety. They 

 were, first, the lack of any governing appliance for the water- 

 wheels ; and, second, the damage to the primary generators caused 

 by the extreme heat and dampness in the underground station. 



The Brush Electric Company, in its original plans and specifica- 

 tions, stipulated that the water-wheel should be governed within 

 reasonable limits ; but this requirement was not met, and the first 

 generator and motor, started up experimentally, showed the neces- 

 sity of this provision. The Brush Company was surprised to re- 

 ceive by telegraph the first intimation that the makers of the water- 

 wheels had wholly neglected such an important matter, but was 

 fortunately able to close the breach at once. A water-wheel gov- 

 ernor, invented and sketched out by Mr. W. B. Devereux, the promi- 

 nent mining engineer, of Aspen, Col., had been placed in the hands 

 of the company some time previously, and working drawings of it 

 had been made at Cleveland. These were at once sent to Cali- 

 fornia, the governors were quickly made, and this source of trouble 

 was overcome. Mr. F. E. Smith, the electrical engineer in charge 

 of the installation, made several modifications of the governor, 

 after watching its performance, which proved of much value, and 

 it has worked perfectly in practical service. 



The second difficulty was met with equal promptness, and like- 

 wise entirely overcome. The temperature of the subterranean 

 power chamber is about 72° F. The atmosphere is almost satu- 

 rated with moisture, — 78 per cent. Any piece of metal taken into 

 it begins immediately to " sweat." The generators, when placed 

 in this chamber, were soon covered and saturated with moisture, 

 and began to show leaks, while the motors above ground were ab- 

 solutely free from any trouble. 



The Brush Company was at once notified of this unanticipated 

 source of difficulty, and Mr. Brush speedily devised a method of in- 

 sulation which would certainly and completely resist the moisture 

 of the sublimated atmosphere. Since its application the generators 

 have worked admirably, and the entire plant is now at work regu- 

 larly, performing its expected duty, and economizing the power 

 available, as stated above. 



The achievement of the Brush Electric Company, in connection 

 with this plant on the Comstock, is a very notable one, and of the 

 greatest interest to mining engineers. The plant is the largest 

 electrical power plant in the world. The company is making a 

 specialty of powerful generators and motors for power transmis- 

 sion and distribution, and is taking large orders for thern, not only 

 in this country, but also for foreign shipments. The latest contract 

 announced is one with the Calumet and Hecla Mining Company 

 for five of the large Brush generators of 130 horse-power, and five 

 of the 80 horse-power Brush motors. A power station will in this 

 case be built above ground for the generators, and the motors will 

 be used for driving pumps underground. The plant goes to the 

 copper-mine at Calumet, Mich. 



A MODEL SCHOOL OF ARCHITECTURE. 



The department of architecture of Columbia College has closed 

 its work for the year with its annual exhibition of drawings. This 

 department was organized eight years ago largely through the 

 liberality of Mr. F. A. Schermerhorn, who contributed the neces- 



sary funds to place it on a firm basis. It has grown with unusuat 

 rapidity, and is now one of the strongest parts of the School of 

 Mines of Columbia College. During the past year, sixty-five stu- 

 dents were registered in the department, an increase of twenty-five 

 over the preceding year. The money furnished by Mr. Schermer- 

 horn has enabled the trustees to supply a liberal collection of ap- 

 paratus, models, books, photographs, and drawings ; and the- 

 whole forms a collection of working material not equalled by an- 

 other institution of the same kind in the country. Columbia is- 

 fortunate, also, in possessing in Professor William R. Ware, wha 

 has charge of this course, a teacher who combines sound technical 

 knowledge with a warm sense of architectural form, and it is to- 

 him that the success of this school of architecture is chiefly due. 



With a large body of students it is, of course, possible to pro- 

 duce large quantities of work, and this was the first noticeable 

 feature in the recent exhibition. Four or five rooms were com- 

 pletely filled with the work of the students. Specimens were 

 shown in all departments of architectural drawing. There were 

 studies in historical ornament, many of them highly spirited 

 sketches ; problems, with details and perspectives ; original de- 

 signs ; carefully prepared elevations ; studies in perspective, in- 

 shades, and shadows; pencil drawings from the cast; memory 

 drawings, — sketches from descriptions of photographs, and highly 

 interesting as showing the attention that must have been given to- 

 the study of styles in order to produce such results ; free-hand 

 sketches of actual buildings and from photographs ; applications- 

 of design and water colors. Nor was the quality of the work less 

 noticeable than the quantity. In a collection of the work of an 

 entire year, some drawings would be necessarily included that are 

 more or less imperfect ; but there were few of these, and they all 

 evinced an extraordinary degree of application on the part of the 

 students, and untiring energy on the part of the teachers and in- 

 structors. 



Many of the pen-and-ink drawings were exquisitely done, and 

 compared very favorably with the work of more experienced 

 draughtsmen. The work of the students in this department does- 

 not cease with the conclusion of the college year. On the con- 

 trary, they are encouraged to enter architects' offices, and to make 

 frequent sketches during the summer. One hundred drawmgs are 

 required to be handed in at the beginning of the college year as 

 evidences of summer work, though each day passed in an architect's- 

 office is accepted as the equivalent for a drawing. The hand and 

 mind of the student are thus kept in constant practice, and there is 

 no doubt but that much of the superior work in this school arises 

 from the fact that the work is constant the year round, and is not 

 interrupted by three months of idleness. One of the most inter- 

 esting sections of the exhibition was that devoted to summer work. 

 The exhibit was large, and included specimens of all kinds of 

 drawings, both from actual buildings and from photographs. The 

 quality of the subjects was an interesting commentary on the man- 

 ner in which the tastes of these young men had been trained. 



The problems of execution included a staircase, with perspective 

 and detail drawings, elevation and details of a classical window, 

 and several other subjects. All these were class-work, and were 

 marked with the criticisms of the professor. Another interesting 

 series were designs for a wrought-iron gate, and some studies for 

 a Roman villa, by the first-year students. Space does not permit, 

 nor is it necessary, to enumerate all the drawings shown. The 

 exhibition was one to have been seen to be appreciated. The 

 work was characterized not only by marked ability on the part of 

 the students, but also testified to the great care and thought dis- 

 played by the teachers. The drawings showed an enthusiasm for 

 the work which is not always to be found among undergraduates. 



A word as to methods. The course in architecture extends over 

 three of the four years' course in the School of Mines. The first 

 college year is devoted by all the students to general studies ; but 

 in the second year the class is divided into sections, each pursuing 

 a technical study. In the course in architecture, drawing is an im- 

 portant feature throughout the three years. In the first year the 

 elements of architecture, with the forms and proportions of the five 

 orders, are taught, together with the study of Greek and Roman 

 architectural history. In the second year technical studies in the 

 mechanics of solids are introduced, and a survey made of the ma- 



